Channel stacking switch (CSS) technology reduces set top box (STB) installation costs and complexity, by requiring only one cable drop per STB, even if the receiver (i.e., the STB) has multiple tuners. The interested reader can find more information about channel stacking switches and their applications in the document entitled “Channel Stacking Switch Technology for Residential DBS Reduces Cabling and STBs”, by M. Ploof, P. Wong and T. Brandon, EE Times-India (www.eetindia.com), November 2007. This document is hereby incorporated herein by reference.
Generally speaking, the CSS provides a plurality of User Bands (UBs) between itself and one or more STBs. A single-tuner STB is assigned one of the user bands and a dual-tuner STB is assigned two of the user bands. The use of a CSS to distribute satellite signals to a group of STBs thus becomes an economical choice when upgrades are envisaged, such as in a single family home when multiple viewing areas are required, and in multi-dwelling units (MDUs).
The EN50495 European Standard, hereby incorporated by reference herein, describes a system for distributing, via a single coaxial cable, signals issued in different satellite frequency bands and having different polarizations to a plurality of STBs. This system is based on the EN61319-1/A11 Digital Satellite Equipment Control Bus specification (frequently referred to as DiSEgC™) in its 1.0 version, also hereby incorporated by reference herein. The EN50495 European Standard describes a user band assignment procedure that relies on a pre-existent configuration defined at installation time, by manually assigning a user band to each STB in a specially designed user interface screen.
This conventional method of assigning user bands has at least three major disadvantages. Firstly, it is an inconvenient procedure to be performed by the installer during the original truck roll and each time a new receiver is added to the system. Due to the highly specialized work required, it is unlikely that customers will be able (or willing) to do this type of work by themselves. Also, the requirement to keep user bands unique implicitly assumes knowledge of previous user band assignments in the same home; this adds time and cost to the overall installation process.
Secondly, for practical reasons, a CSS unit may have multiple output ports, each handling a subset of user bands. Moving a receiver to another port requires re-assigning a user band, otherwise the receiver won't work. This again would potentially require the on-site presence of a technician and could be the source of significant customer dissatisfaction.
Thirdly, a critical failure condition (e.g. a power outage) may require a manual reconfiguration for one or more receivers in the entire system. This is again a very inconvenient process, and rolling trucks after a power outage is not something that both customers and signal distribution companies would enjoy.
Against this background, it is clear that the industry is in need of an improved user band assignment methodology.